Purpose :
A single centre retrospective review was undertaken to investigate the demographics and factors influencing visual acuity (VA) recovery of patients presenting with MEWDS.

Methods :
Chart review of patients presenting to Moorfields Eye Hospital, UK with clinical features of MEWDS were analysed using standardised accepted clinician consensus criteria. Patients with incomplete records or other co-morbidities were excluded. Best-corrected VA was converted to logMAR.Multimodal imaging, including spectral domain OCT (SD-OCT), fundus autofluorescence (FAF), fluorescein angiography and indocyanine green angiography was available for most patients. Minimum follow-up from presentation required for inclusion was 3 months.

Results :
72 eyes of 68 patients presenting between 2011 and 2017 met inclusion criteria.Mean age of onset was 28.6 years (range 17-51). The female:male ratio was 4:1. 6% were bilateral. The mean presenting VA was 0.3 logMAR, and final recovered VA was 0.05 logMAR. The percentage of eyes recovering vision to 0.0 logMAR or better was 72.4% and 27.6% had final VA between 0.0 logMAR and 0.18 logMAR. Final VA correlated highly with presenting acuity (Spearman rho = 0.53, p<.001). Mean presenting VA of those patients who failed to recover to 0.0 LogMAR (final VA range > 0.0 to 0.18 logMAR) were significantly worse than those recovering to 0.0 logMAR or better (group mean LogMAR 0.53 vs 0.22, p=.003). Neither age, nor gender influenced final VA outcome. Imaging assessments revealed differences in extent and degree of confluence of FAF and ICGA changes, as well as extent of ellipsoid disruption on SD-OCT at presentation between those patients who completely recovered good VA versus those who didn't. Persistence of foveal granularity on near-infrared reflectance imaging, outer retinal layers' disruption (ie external limiting membrane, ellipsoid zone) on OCT at the last visit, with at least 3 months follow up were negative prognostic factors in terms of VA recovery.

Conclusions :
This large series confirms that MEWDS is predominantly a disease of young females. Not all patients recover normal VA, with 27.6% failing to recover to 0.0 logMAR. In this sense the disease isn't always benign. Baseline VA is an important prognostic factor for final VA. Multimodal imaging may recognise biomarkers of incomplete functional recovery.

This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.